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Category: Physics

The value of the Hubble Constant and the fate of the universe

The value of the Hubble Constant and the fate of the universe

Corey S Powell writes: What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant. The Hubble Constant can be…

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Is a grand theory of everything finally within reach?

Is a grand theory of everything finally within reach?

James Wells writes: When trying to explain what motivates me as a physicist, the film A Passage to India (1984) comes to mind. Based on the play by Santha Rama Rau, adapted from the novel by E M Forster, it describes the fallout from a rape case in the fictional city of Chandrapore, during the British Raj in India in the 1920s. What keeps the viewer’s attention is the subtlety of the relationships between the characters – particularly the fragile…

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With constructor theory, the physicist, Chiara Marletto, invokes the impossible

With constructor theory, the physicist, Chiara Marletto, invokes the impossible

Amanda Gefter writes: They say that in art, constraints lead to creativity. The same seems to be true of the universe. By placing limits on nature, the laws of physics squeeze out reality’s most fantastical creations. Limit light’s speed, and suddenly space can shrink, time can slow. Limit the ability to divide energy into infinitely small units, and the full weirdness of quantum mechanics blossoms. “Declaring something impossible leads to more things being possible,” writes the physicist Chiara Marletto. “Bizarre…

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A tiny particle’s wobble could upend the known laws of physics

A tiny particle’s wobble could upend the known laws of physics

Dennis Overbye writes: Evidence is mounting that a tiny subatomic particle seems to be disobeying the known laws of physics, scientists announced on Wednesday, a finding that would open a vast and tantalizing hole in our understanding of the universe. The result, physicists say, suggests that there are forms of matter and energy vital to the nature and evolution of the cosmos that are not yet known to science. “This is our Mars rover landing moment,” said Chris Polly, a…

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Physicists nail down the ‘magic number’ that shapes the universe

Physicists nail down the ‘magic number’ that shapes the universe

Natalie Wolchover writes: As fundamental constants go, the speed of light, c, enjoys all the fame, yet c’s numerical value says nothing about nature; it differs depending on whether it’s measured in meters per second or miles per hour. The fine-structure constant, by contrast, has no dimensions or units. It’s a pure number that shapes the universe to an astonishing degree — “a magic number that comes to us with no understanding,” as Richard Feynman described it. Paul Dirac considered…

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Physics and information theory give a glimpse of life’s origins

Physics and information theory give a glimpse of life’s origins

Natalie Elliot writes: How did life originate? Scientists have been studying the question for decades, and they’ve developed ingenious methods to try to find out. They’ve even enlisted biology’s most powerful theory, Darwinian evolution, in the search. But they still don’t have a complete answer. What they have hit is the world’s most theoretically fertile dead end. When scientists look for life’s origins, they usually work in one of two directions. They work backwards in time through the record of…

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The hidden magnetic universe begins to come into view

The hidden magnetic universe begins to come into view

Natalie Wolchover writes: Anytime astronomers figure out a new way of looking for magnetic fields in ever more remote regions of the cosmos, inexplicably, they find them. These force fields — the same entities that emanate from fridge magnets — surround Earth, the sun and all galaxies. Twenty years ago, astronomers started to detect magnetism permeating entire galaxy clusters, including the space between one galaxy and the next. Invisible field lines swoop through intergalactic space like the grooves of a…

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Donald Trump is lying about taking hydroxychloroquine, a lot of people say

Donald Trump is lying about taking hydroxychloroquine, a lot of people say

Vogue reports: President Donald Trump announced at a White House event on Monday that he has been taking the antimalarial drug hydroxychloroquine for “a couple of weeks” as a preventive measure against COVID-19. A lot of people don’t believe him. Immediately after the startling announcement, dozens of critics took to Twitter to doubt the president’s claim. “Raise your hand if you think that Trump is lying about taking #Hydroxychloroquine,” tweeted the widely followed health advocate Peter Morley. “I’m gonna go…

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Lunch with Freeman Dyson

Lunch with Freeman Dyson

Siobhan Roberts writes: Lunchtime in the cafeteria at the Institute for Advanced Study in Princeton, N.J. — sometimes called the Institute for Advanced Dining — is a heady scene, and Freeman Dyson, who died last week at 96, was a regular fixture, arriving with reading material tucked under his arm. One day about 10 years ago, Dr. Dyson put down his tray of food at the physics table and joined the conversation. Nima Arkani-Hamed, a professor in the institute’s School…

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Do we live in a multiple universe?

Do we live in a multiple universe?

David J. Eicher writes: Decades of astrophysical research beginning in the late 19th century established the universe as we see it, culminating with the Big Bang theory. We now know the universe is about 13.8 billion years old and at least 150 billion trillion miles across. But in recent years, astronomers have begun to address a staggering possibility — the universe we can observe, and in which we live, may be one of many that makes up the cosmos. The…

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How far is it to the edge of the Universe?

How far is it to the edge of the Universe?

Ethan Siegel writes: If you were to go as far out into space as you can imagine, what would you encounter? Would there be a limit to how far you could go, or could you travel a limitless distance? Would you eventually return to your starting point, or would you continue to traverse space that you had never encountered before? In other words, does the Universe have an edge, and if so, where is it? Believe it or not, there…

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Our place in the universe will change dramatically in the next 50 years – here’s how

Our place in the universe will change dramatically in the next 50 years – here’s how

Is there anybody out there? Greg Rakozy/Unsplash, CC BY-SA By Robin Smith, Sheffield Hallam University In 1900, so the story goes, prominent physicist Lord Kelvin addressed the British Association for the Advancement of Science with these words: “There is nothing new to be discovered in physics now.” How wrong he was. The following century completely turned physics on its head. A huge number of theoretical and experimental discoveries have transformed our understanding of the universe, and our place within it….

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Quantum physics: Study suggests objective reality doesn’t exist

Quantum physics: Study suggests objective reality doesn’t exist

Gearoid Hayes/Flickr, CC BY-SA By Alessandro Fedrizzi, Heriot-Watt University and Massimiliano Proietti, Heriot-Watt University Alternative facts are spreading like a virus across society. Now it seems they have even infected science – at least the quantum realm. This may seem counter intuitive. The scientific method is after all founded on the reliable notions of observation, measurement and repeatability. A fact, as established by a measurement, should be objective, such that all observers can agree with it. But in a paper…

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Is a new particle changing the fate of the universe?

Is a new particle changing the fate of the universe?

Paul Sutter writes: Astronomers around the world are in a bit of a tizzy because they can’t seem to agree about how fast the universe is expanding. Ever since our universe emerged from an explosion of a tiny speck of infinite density and gravity, it has been ballooning, and not at a steady rate, either — the expansion of the universe keeps getting faster. But how quickly it’s expanding has been up for a dizzying debate. Measurements of this expansion…

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Materialism alone cannot explain the riddle of consciousness

Materialism alone cannot explain the riddle of consciousness

Adam Frank writes: Materialism holds the high ground these days in debates over that most ultimate of scientific questions: the nature of consciousness. When tackling the problem of mind and brain, many prominent researchers advocate for a universe fully reducible to matter. ‘Of course you are nothing but the activity of your neurons,’ they proclaim. That position seems reasonable and sober in light of neuroscience’s advances, with brilliant images of brains lighting up like Christmas trees while test subjects eat…

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Can physicists rewrite the origin story of the universe?

Can physicists rewrite the origin story of the universe?

Jess Romeo writes: During a 2015 conference on theoretical cosmology at Princeton University, Roger Penrose, a pioneer in the field of mathematical physics, was asked to speak on a panel about the origin of the universe. For decades, the leading theory had been that, during roughly the first trillionth of a trillionth of a nanosecond following the Big Bang, there was a single period of extremely rapid expansion, known as inflation, that formed the universe we observe today. When it…

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